---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 11/11/14: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:47 AM - Re: VOR Antenna / Balun / Lead (Robert L. Nuckolls, III) 2. 06:35 AM - Bew Battery? (Eric M. Jones) 3. 07:54 AM - alternator / generator (Ken Ryan) 4. 08:03 AM - Re: RS422 - RS232 (user9253) 5. 11:37 AM - Re: Radio Transmits Poorly Only When On The Ground (DaveG601XL) 6. 12:46 PM - Re: RS422 - RS232 (Henry Hallam) 7. 05:15 PM - Re: VOR Antenna / Balun / Lead (Chuck Birdsall) 8. 06:38 PM - Re: RS422 - RS232 (Robert L. Nuckolls, III) 9. 06:42 PM - Re: alternator / generator (Robert L. Nuckolls, III) 10. 08:25 PM - Re: alternator / generator (Ken Ryan) ________________________________ Message 1 _____________________________________ Time: 05:47:21 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: VOR Antenna / Balun / Lead At 01:15 2014-11-11, you wrote: The VOR antenna balun setup on my 1972 Cherokee has come apart (age, corrosion). Looks like RG-58 for the lead/balun. There's enough corrosion on the antenna lead screws and elsewhere that has me thinking about replacing the antenna. So, I have the following questions: Is there any practical difference between antennas with a built-in balun and a BNC connection (i.e. RAMI AV-525), and a VOR antenna with the balun in the antenna lead (such as the RAMI AV-12)? (Other than cost and having to spend a short amount of time making the balun ...) I presume that the antenna configuration being considered for replacement has bee functioning satisfactorily. It's a toss up between the two antennas for performance. Baluns are not hard to build but the antenna with the built in matching is fitted with a BNC connector. Much 'cleaner' termination of coax than ring terminals. Is there a perceptible difference between RG-58 and RG-400 for the antenna lead? There's enough slack in the current antenna lead that I could simply cut off the bad part of the old cable and install a BNC connector... (but I'd still have 40+ year old cable.) Not that you can tell from the pilot's seat. It would probably work just fine. I do have a short (<10ft) length of RG-400 so I could try to replace the bad section of the existing lead, make a new balun and try to rescue the existing antenna from the oxidation. This would add two BNC connectors in the antenna lead run. Properly done, would the connectors provide a significant loss of signal? Or would I be better off to spend the $$ and buy enough RG400 to make the whole run? If you're doing the work yourself, the $risks$ are low. Carry out the experiment and tell us what you discover. "Corrosion" on the stock 'whiskers' is cosmetic and easily cleaned off to effect connection to a new balun. You can fabricate the balun on the end of enough coax to make the run into better environments where the RG-58 is in better shape and splice in with BNC-CM/CF pair. It's a $low$, low risk experiment with good odds of working just fine. Bob . . . ________________________________ Message 2 _____________________________________ Time: 06:35:01 AM PST US Subject: AeroElectric-List: Bew Battery? From: "Eric M. Jones" Worth seeing. I have no opinions other than the fact that the proof is in the pudding. Design News Daily Update: http://emailactivity1.ecn5.com/engines/publicPreview.aspx?blastID'2652&emailID=61833118 -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=433379#433379 ________________________________ Message 3 _____________________________________ Time: 07:54:54 AM PST US From: Ken Ryan Subject: AeroElectric-List: alternator / generator The Rotax 914 wiring diagram shows an integrated generator with external regulator-rectifier and an external alternator with built in regulator. It looks like the integrated generator is disconnected from the battery (by relay) when the master is off but the external alternator remains connected. The text indicates the integrated generator will run the battery down if not disconnected, but does not say that for the external alternator. Does this make sense? ________________________________ Message 4 _____________________________________ Time: 08:03:36 AM PST US Subject: AeroElectric-List: Re: RS422 - RS232 From: "user9253" It is my understanding that a mode S transponder must have the EXTENDED SQUITTER feature to be ADS-B compliant in 2020. The data contained in extended squitter transmissions tells the ground station what ADS-B hardware is installed in the aircraft. If the hardware does not meet government regulations, the ground station will not transmit traffic and weather back to the aircraft after 2020. And using hardware that is not certified might be in violation of FARs. An avionics shop like Steinair should be consulted before spending time and money. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=433384#433384 ________________________________ Message 5 _____________________________________ Time: 11:37:11 AM PST US Subject: AeroElectric-List: Re: Radio Transmits Poorly Only When On The Ground From: "DaveG601XL" Bob, I finally got back out to the airport with an assistant and my hand-held radio. My all-metal airplane has an Icom A-200 radio going through a PS Engineering PM501 intercom, but I also have aux headset jacks that go directly to the Icom. I transmitted both engine-off and engine-on. We set up a sequence where I used both my Bose X headset and a cheap passive headset. I swapped them between the pilot and co-pilot intercom jacks as well as the aux radio jack. I also varied the engine RPM to see if low voltage was an issue as I have a Jabiru with a dynamo alternator that does not charge at idle. We could not reproduce garbled transmissions with any combination. We did note that the anything transmitting out of the pilot intercom jacks had a slight more static that the other jacks. The next time I go flying with some friends and their aircraft, I will repeat the test again with them listening in on airplane radios. Thanks, -------- David Gallagher Zodiac 601 XL-B: flying, 280+ hours now Next project under construction: Finish my father's Aircamper Read this topic online here: http://forums.matronics.com/viewtopic.php?p=433393#433393 ________________________________ Message 6 _____________________________________ Time: 12:46:42 PM PST US From: Henry Hallam Subject: Re: AeroElectric-List: RS422 - RS232 That will convert the logic levels (physical layer) but are the protocols known to be compatible? i.e. does the 432W (I didn't realize there was such a thing) send messages in a format that the transponder can understand, even after converting to RS-232? Henry On Tue, Nov 11, 2014 at 1:06 AM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 18:09 2014-11-10, you wrote: > > > In starting to think about ADS-B one way to get out only would be a Mode-S > transponder hooked to the existing Garmin 432W. The 432 speaks RS232 and > the transponder slide in replacement speaks RS422. There are converters > available for under 20 bucks. Is it that simple? > > > If you want to build on, here's a schematic. > > [image: []] > > > Bob . . . > > * > > > * > > ________________________________ Message 7 _____________________________________ Time: 05:15:18 PM PST US From: Chuck Birdsall Subject: Re: AeroElectric-List: VOR Antenna / Balun / Lead Thanks! I'll try making a baling with the RG400 I have first and report bac k. Chuck On Nov 11, 2014, at 07:46, Robert L. Nuckolls, III wrote: At 01:15 2014-11-11, you wrote: The VOR antenna balun setup on my 1972 Cherokee has come apart (age, corrosi on). Looks like RG-58 for the lead/balun. There's enough corrosion on the a ntenna lead screws and elsewhere that has me thinking about replacing the an tenna. So, I have the following questions: Is there any practical difference between antennas with a built-in balun and a BNC connection (i.e. RAMI AV-525), and a VOR antenna with the balun in th e antenna lead (such as the RAMI AV-12)? (Other than cost and having to spe nd a short amount of time making the balun ...) I presume that the antenna configuration being considered for replacement has bee functioning satisfactorily. It's a toss up between the two antennas for performance. Baluns are not hard to build but the antenna with the built in matching is fitted with a BNC connector. Much 'cleaner' termination of coax than ring terminals. Is there a perceptible difference between RG-58 and RG-400 for the antenna l ead? There's enough slack in the current antenna lead that I could simply c ut off the bad part of the old cable and install a BNC connector... (but I'd still have 40+ year old cable.) Not that you can tell from the pilot's seat. It would probably work just fine. I do have a short (<10ft) length of RG-400 so I could try to replace the bad section of the existing lead, make a new balun and try to rescue the existi ng antenna from the oxidation. This would add two BNC connectors in the ant enna lead run. Properly done, would the connectors provide a significant lo ss of signal? Or would I be better off to spend the $$ and buy enough RG400 to make the whole run? If you're doing the work yourself, the $risks$ are low. Carry out the experiment and tell us what you discover. "Corrosion" on the stock 'whiskers' is cosmetic and easily cleaned off to effect connection to a new balun. You can fabricate the balun on the end of enough coax to make the run into better environments where the RG-58 is in better shape and splice in with BNC-CM/CF pair. It's a $low$, low risk experiment with good odds of working just fine. Bob . . . ========================== ======== ========================== ======== ========================== ======== ========================== ======== ________________________________ Message 8 _____________________________________ Time: 06:38:00 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RS422 - RS232 At 14:45 2014-11-11, you wrote: >That will convert the logic levels (physical layer) but are the >protocols known to be compatible? i.e. does the 432W (I didn't >realize there was such a thing) send messages in a format that the >transponder can understand, even after converting to RS-232? 232/422/etc ARE electrical/handshake standards . . . and do not describe data formats. http://tinyurl.com/buupe http://tinyurl.com/2twp68 Most aviation serial data exchanges are at 9600 bits/sec, 8 bit word, no parity, 1 stop bit. This data framing is independent of the conduit carrying the data. 422 is often used as an "extender" for 232. 232 is not suited for long runs between devices that might have large differences in ground potential (ground loop noises). 422 is twisted pair with much greater noise immunity. We had some equipment at Hawker/Beech where I converted 232 to 422 and back to 232 some 100 feet away. Somewhere in my software cookie jar, I have a routine that looks at the serial data input port and measures the bit rate. You can squirt anything from 600 to 19,600 bits per second at it . . . and it will sync up and go to work. You still have to do the 8,N,1 thingy but bit rate is optional. You'll need to consult the installation manuals for the systems you wish to link . . . odds are they both speak 9600,8,N,1 but it's a good thing to check. Bob . . . ________________________________ Message 9 _____________________________________ Time: 06:42:07 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: alternator / generator At 09:52 2014-11-11, you wrote: >The Rotax 914 wiring diagram shows an integrated generator with >external regulator-rectifier and an external alternator with built >in regulator. It looks like the integrated generator is disconnected >from the battery (by relay) when the master is off but the external >alternator remains connected. The text indicates the integrated >generator will run the battery down if not disconnected, but does >not say that for the external alternator. Does this make sense? It makes sense to Rotax . . . but Rotax doesn't build or fly airplanes. This is a case similar the one where Garmin recommended an electrical sytem architecture in the back of one of their EFIS installation manuals. Never a good idea. How do YOU want your airplane to work? Check out Z-13/8, Z-12, and Z-14 in the 'Connection along with their companion narratives in Chapter 17 and YOU decide what makes sense for you. Bob . . . ________________________________ Message 10 ____________________________________ Time: 08:25:55 PM PST US From: Ken Ryan Subject: Re: AeroElectric-List: alternator / generator Sheesh. Let me try again: The Rotax (major, major manufacturer of aircraft engines) wiring diagram seems to indicate that the "integrated generator" (which has an external regulator-rectifier) must be disconnected from the battery to avoid discharging the battery when it is not turning. On the other hand, the external "alternator" (which has a built in regulator) is wired directly to the battery, indicating that it does NOT need to be disconnected to avoid running down the battery. Is this consistent with you knowledgeable folks' understanding of these sorts of generators and alternators? On Tue, Nov 11, 2014 at 5:41 PM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > nuckolls.bob@aeroelectric.com> > > At 09:52 2014-11-11, you wrote: > >> The Rotax 914 wiring diagram shows an integrated generator with external >> regulator-rectifier and an external alternator with built in regulator. It >> looks like the integrated generator is disconnected from the battery (by >> relay) when the master is off but the external alternator remains >> connected. The text indicates the integrated generator will run the battery >> down if not disconnected, but does not say that for the external >> alternator. Does this make sense? >> > > It makes sense to Rotax . . . but Rotax doesn't > build or fly airplanes. This is a case similar > the one where Garmin recommended an electrical sytem > architecture in the back of one of their EFIS > installation manuals. Never a good idea. > > How do YOU want your airplane to work? Check out > Z-13/8, Z-12, and Z-14 in the 'Connection along > with their companion narratives in Chapter 17 > and YOU decide what makes sense for you. > > > Bob . . . > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.